Article of manufacture



June 18,

E. A. TOOHEY 2,005,304

ARTICLE OF MANUFACTURE Filed July so, 1932 INVENTOR Edward A. Too/0g.

' Hid M ATTORNEY Patented June 18, 1.)35

UNITED STATES PATENT oFFi'cE ARTICLE OF MANUFACTURE Edward A. Toohey, Somerville, N. J., aslignor to Johns-Manville Corporation, New York, N. Y., a corporation of New York Application July 30, 1932, Serial No. 626,493

2 Claims. (Cl. 154-45) This invention relates to a void-containing ar- The manner in which the soft, yielding sheets ticle of manufacture, particularly to an improved rest upon each other and seal the voids is indithermal insulating article provided with voids cated in the case of the void 6. defined between soft, yielding sheets of felted Because of the softness of the sheets and the 5 fibers. consequent fact that tubular insulation made 5 The invention comprises thermal insulating therefrom is subject normally to distortion of pipe covering in the form of a tube including soft shape, it is desirable to use an inwardly disposed, and yielding, spirally wound, alternating sheets strengthening and shape-retaining member 1 and of irregular surface and other sheets, not meshalso an outwardly disposed, strengthening and ing therewith, that define voids between them and shape-retaining wrapper 8. The member 'i may 10 the sheets of irregular surface. Thus, the inconsist of asphalt-impregnated rag felt, say a vention comprises pipe covering resulting from roofing paper that, before impregnation, weighs making a composite of sheets of plain and in- 6 to 8 ounces per square yard. 1 Theouter dented wool felt and spirally winding the comstrengthening and wrapping member may con- 5 posite into tubular form. sist of the same type of roofing paper. Also, there Pipe covering has been made heretofore by may be disposed around the tubular covering a spirally winding indented asbestos paper, for exjacket 9 that may consist suitably of light cotton ample, into tubular form. The voids between the sheeting or heavy paper. The jacket, if paper,/ indentations and the adjacent sheets in the tubumay be an aluminum-coated, kraft paper.

o lar article are not sealed, unless a very special y The tubular pipe covering may be sawed comtype of structure is provided purposely to seal pletely through on one side, as indicated at Hi,

the voids. and scored, that is, sawed almost completely There has now been found a method of making through at the back, as indicated at I I, whereby a particularly effective thermal insulating article the covering is adapted to be opened for concontaining voids sealed in a very simple and venient installation around a pipe to be insuconvenient manner. lated or for removal therefrom. After being in- The invention is illustrated in the figure which stalled around a pipe, the covering may be held in shows a perspective view of a preferred type of position by metal bands l2, as well as by adhethermal insulating article, with parts broken away sively securing the flap l3 of the jacket over the rm for clearness of illustration. joint In.

In the figure there is shown a pipe i with sec- In making the article of the present invention, tional tubular thermal insulating pipe covering 2 there is first made soft, yielding sheets of fibrous in position around the pipe. The pipe covering material. Thus, there may be made a. wool felt includes soft, yielding sheets 3 of felted fibers, weighing suitably 6 to 8 ounces per square yard.

the said sheets being provided with depressions The wool felt may be made by beating woolen 35 or irregularities of surface, say, with indentarags with water in a paper beater and collecting tions 4. In the pipe covering these sheets 3 are the beaten fibers to form a felt on a paper maalternated and composited with sheets 5 of simchine of conventional design. ilar composition or properties, but of surface that A part of the thus formed felt is submitted to 40 does not mesh or nest with the sheets 3. Thus, treatment to provide irregularities of surface. A 40 the sheets 5 may have a regular surface, as, for felt may be passed between a pair of coacting example, cylindrical. rollers or pressed between coacting dies pro- The sheets used in the insulating article should vided, in either case, with meshing, pronounced be so soft and yielding that, when composited irregularities of surface, to impress the desired 5 together in simple manner, the sheets will rest irregulariti s of surface upon the wool felt. It

upon each other and seal the voids or spaces is convenient to have the wool felt slightly moist between the indentations, for example, in the one at the time that it is pressed between the rollers sheet and the surface of the juxtaposed sheet. or dies.

For this purpose, wool felt has been found par- After being so provided with irregularities of ticularly satisfactory. Also, there may be used a surface, the felt is dried and is composited with 50 mixture of wool fibers and wood pulp, say news felt of the same kind but with surface of shape print, the said mixture including a high proporthat will not nest or mesh with the said irregtion of wool. Another sheet that may be used ularities. In compositing two sheets of unlike is one consisting largely of short, soft hairs in surface, one of the sheets is treated in localized 5 felted form. areas with an adhesive, say with an aqueous solution of silicate of soda, and is then pressed upon the other sheet so that the two sheets are united by the adhesive. The pressure used in the compositing is substantially less than the pressure which would cause obliteration of the irregularities of surface of a sheet being composited with another sheet.

The composited sheets are then treated, on one side and in limited areas, with an adhesive. Thus, a solution of sodium silicate may be applied in narrow bands, say 1 to 2 inches apart and extending across one face of the compoeited sheets. The composited sheets thus treated with. adhesive are then wrapped around a mandrel in such manner as to form a spirally wound article in which the two sheets of dissimilar surface alternate with each other.

When the winding has given a tube of desired thickness of wall, the winding is discontinued, unused composited sheet material is removed, and the tube is sawed at position l6 and scored at position ii.

If the inner strengthening and shape-retaining member is to be used, this member is placed around the mandrel before the winding of the composited, soft, yielding sheets is begun. This strengthening member is provided on its outer surface with adhesive which secures it, in the finished article, to the inner sheet of the thermal insulation. If the outer strengthening and shape-retaining member is to be used, it is applied'to the outside of the spirally wound composite. Finallythe jacket is applied. If the jacket is of cotton sheeting or the like, it is suitably applied with 'a starch adhesive. The aluminum-coated kraft paper jacket, on the other hand, is applied, preferably, with an aqueous solution of sodium silicate.

A thermal insulating article so made has certain features in addition to those that have been indicated. The article is light in weight, very effective in thermal insulation and is particularly adapted for use under conditions which do not favor the formation of dew within the insulation or at temperatures that are not so high as to cause disintegration by heat. Thus, the article is particularly adapted for use in insulating water lines. A typical product made as described, of size to flta 3" pipe and of wall thickness 1", and with indented sheets of wool felt alternating with sheets of wool felt of regular surface, weighed approx'mately 1.75 pounds per linear foot, after being maintained for some time at a temperature of 212 F. This same pipe covering showed a heat transfer of 0.356 B. t. u.

per square foot, per hour, for each 1 degree F. of difference of temperature between the warm and cool surfaces. Not only is the material light-weight and efficient but also it is convenlent and economical to manufacture.

The backing sheet, which is alternated with the sheet of irregular surface, is preferahiy of regular surface, say, plane in a flat insulating article or cylindrical in the tubular. However, other types of backing sheets may be used, as, for example, crinkled or creped soft felts. Also, there may he used, either as the backing sheet or as the sheet composited therewith, soft wool felts containing therein particles of sponge, cork or corn cob and made by the method described in U. 8. Patent 1,218,679 to Manville.

In general, the sheets that are composited should be so soft and yielding and the irregularities of surface of one or both of the sheets should be of such a nature that the sheets will tend to collapse upon each other and provide sealed voids between them, with the consequent minim zing of air circulation between the various voids. The sheets of the type described are somewhat fuzzy in the sense that they have fibers projecting 'from their surfaces. These projecting fibers, as well as the collapsing of the sheets themselves, tend to seal the voids defined between two adjacent sheets or to circulation of air between the said voids. This discontinuous irregularities of surface, of some of the said sheets, forming voids between adjacent sheets, the adjacent sheets being collapsed upon each other, whereby there is minimized the circulation of air between the voids defined by two adjacent sheets.

2. Thermal insulation, as described in the foregoing claim, having the form of a tube subject normally to distortion of shape and including shape-retaining and strengthening means disposed within the said tube and united thereto.

EDWARD A. TOOHEY. 

